Brunt is better than Field. End of story really...
It's not end of story (at least not for me
).
It's a sliding scale in that Brunt is getting further past his peak age and Field is getting closer to reaching peak age, though not close to it yet.
So if you class the main attributes necessary for CM/DM as (in no particular order) passing, tackling, movement. (Experience shouldn't come into it as that is an immeasurable and not am actual part of the game).
Tackling - I think even you would find it tricky to make a case for Brunt being the better tackler...especially after the Villa game (liability) ??
Passing, Brunt has the occasional 'worldy' assist but we haven't seen Field have chance to settle in and feel like he belongs. (Megson reckoned Field had the best passing range at the club).
Movement, well I confidently predict Field will have the better game in game out engine this season. Brunt's best efforts in the past 18 months or so have been from the bench when he knows he only has 20 or 25 minutes to get through.